Researchers at the Feinstein Institute for Medical Research have successfully created cartilage using a MakerBot 3D printer. The team made use of the technology to quickly and affordably prototype and refine the bioprosthesis, and even used it to create a low-cost bioreactor to facilitate the growth of the cells.
Tracheal damage can be caused by various injuries including blunt trauma and tumors, and it’s routinely difficult to treat. Traditional tracheal surgery methods are limited, particularly in children, by the amount of the trachea that can be removed to make room for reconstruction. If too much of the trachea were to be removed, then the level of tension on reconnected ends would be too great, resulting in potentially disastrous complications.
"Making a windpipe or trachea is uncharted territory'" said Todd Goldstein, an investigator at the Feinstein Institute. "It has to be rigid enough to withstand coughs, sneezes and other shifts in pressure, yet flexible enough to allow the neck to move freely."
The new method tackles the problem by employing tissue engineering, in which cartilage is grown from a mixture of cells called chondrocytes, nutrients to feed the growth, and collagen to hold the whole process together. While this is an established method of making cartilage, getting it to grow into the correct shape for treatment is rather more difficult.
That’s where 3D printing comes in. The team used a MakerBot Replicator 2X Experimental 3D Printer to create a scaffolding that was then covered in a bio-ink consisting of the mixture of collagen and chondrocytes. The PLA-constructed frame provides structure to the mixture as it grows into cartilage.
By using 3D printing, the team was able to make numerous prototypes of the scaffolding, examining and modifying the designs over a short period of time. It received help from MakerBot when it came to optimizing design files, as well as modifying the printer itself to print a mixture of PLA and biomaterial. The MarkerBot Thingiverse website also helped provide details on modifying the printer to print PLA with one extruder and biomaterial with the other.
The modifications allowed the team to avoid purchasing an expensive, purpose-built bioprinter, dramatically lowering the cost of the project and making it viable to pursue. They found that the standard MakerBot PLA filament was suitable for use in the bioprothesis, as the heat from the extruder head sterilizes the material during construction.
Printing a 2-inch (5 cm) long section of windpipe takes less than two hours, after which it needs to be placed in a bioreactor, which acts like a rotisserie – keeping the cells at optimum temperature while allowing them to grow evenly.
In order to avoid the high cost of purchasing a new bioreactor (between US$50,000 and $150,000), Goldstein once again resorted to 3D printing, using the MakerBot printer to make gears and other parts, converting an incubator to suit the needs of the project.
The results of the research are promising, with Goldstein stating that, "The cells survived the 3D printing process, were able to continue dividing, and produced the extracellular matrix expected of tracheal chrondrocytes."
While further study is required before the research can be put into practice, it has the potential to change the face of tracheal surgery. The impact will be particularly significant for pediatric applications, as the graft’s biological nature allows the patient to grow, removing existing limitation in regard to the physical length of reconstruction. Additionally, the method can also be used to create a branching bioprosthesis, making it viable for surgery on the tracheal carina and bronchi.
Check out the video below for a look at the institutes work with 3D printing.
Sources: MakerBot, Feinstein Institute for Medical Research
